Cyrus Hall McCormick (1809-1884) developed the first effective reaper on this farm, Walnut Grove. This invention, successfully demonstrated in July 1831, revolutionized world agricultural production, for it permitted the farmer to reap with minimal effort as much grain as he could sow. McCormick patented the machine in 1834 and made improvements in the 1840s. Commercial manufacture of the reaper began at Walnut Grove. In 1847, McCormick, in partnership with his brother Leander, founded the McCormick Harvesting and Machine Company in Chicago and became one of the most successful manufacturers in America’s industrial age. Walnut Grove is now owned by Virginia Tech, which operates the farm as the Shenandoah Valley Research Station. The log workshop where the first reaper was built and the adjacent log mill are exhibited to the public.